To reduce the potential signaling traffic in IP multimedia subsystem (IMS), the session establishment procedures were investigated. The serving call session eontrol function (S-CSCF) is the major bottleneck in IMS...To reduce the potential signaling traffic in IP multimedia subsystem (IMS), the session establishment procedures were investigated. The serving call session eontrol function (S-CSCF) is the major bottleneck in IMS and the existing 3GPP service triggering algorithm (STA) based on initial filter eriteria (iFC) increases the end-to-end session setup delay remarkably. To reduce the session setup delay and improve the system performanee, a SIP response message based filter criteria (rFC) was proposed. Based on the rFC, a SIP response message based STA (RSTA) was further proposed. The modeling and theoretical analysis of 3GPP STA and RSTA were presented. Simulation results show that, compared with 3GPP STA, the RSTA can avoid the additional signaling traffie load of the S-CSCF and application server (AS) effectively, reduce the session setup delay eonsiderably, increase the throughput of the S-CSCF and improve the quality of service (QoS) of IMS network.展开更多
A novel thermal-assisted ultra-violet(UV) photocatalysis digestion method for the determination of total phosphorus(TP) in water samples was introduced in this work. The photocatalytic experiments for TP digestion wer...A novel thermal-assisted ultra-violet(UV) photocatalysis digestion method for the determination of total phosphorus(TP) in water samples was introduced in this work. The photocatalytic experiments for TP digestion were conducted using a 365 nm wavelength UV light and Ti O2 particles as the photocatalyst. Sodium tripolyphosphate and sodium glycerophosphate were used as the typical components of TP and the digested samples were then determined by spectrophotometry after phosphomolybdenum blue reaction. The effects of operational parameters such as reaction time and temperature were studied for the digestion of TP and the kinetic analysis of two typical components was performed in this paper. The pseudo-first-order rate constants k of two phosphorus compounds at different temperatures were obtained and the Arrhenius equation was employed to explain the effect of temperature on rate constant k. Compared with the conventional thermal digestion method for TP detection, it was found that the temperature was decreased from 120 °C to 60 °C with same conversion rate and time in this thermal-assisted UV digestion method, which enabled the digestion process work at normal pressure. Compared with the individual ultra-violet(UV) photocatalysis process, the digestion time was also decreased from several hours to half an hour using the thermal-assisted UV digestion method. This method will not lead to secondary pollution since no oxidant was needed in the thermal-assisted UV photocatalysis digestion process, which made it more compatible with electrochemical detection of TP.展开更多
基金Supported by National Science Fund for Distinguished Young Scholars (No. 60525110)National Basic Research Program of China (No.2007CB307100, 2007CB307103)+1 种基金Program for New Century Excellent Talents in University (No. NCET-04-0111 )Development Fund Project for Electronic and Information Industry (Mobile Service and Application System Based on 3G)
文摘To reduce the potential signaling traffic in IP multimedia subsystem (IMS), the session establishment procedures were investigated. The serving call session eontrol function (S-CSCF) is the major bottleneck in IMS and the existing 3GPP service triggering algorithm (STA) based on initial filter eriteria (iFC) increases the end-to-end session setup delay remarkably. To reduce the session setup delay and improve the system performanee, a SIP response message based filter criteria (rFC) was proposed. Based on the rFC, a SIP response message based STA (RSTA) was further proposed. The modeling and theoretical analysis of 3GPP STA and RSTA were presented. Simulation results show that, compared with 3GPP STA, the RSTA can avoid the additional signaling traffie load of the S-CSCF and application server (AS) effectively, reduce the session setup delay eonsiderably, increase the throughput of the S-CSCF and improve the quality of service (QoS) of IMS network.
基金Supported by the National Natural Science Foundation(61372053)the National High Technology Research and Development Program(2012AA040506)
文摘A novel thermal-assisted ultra-violet(UV) photocatalysis digestion method for the determination of total phosphorus(TP) in water samples was introduced in this work. The photocatalytic experiments for TP digestion were conducted using a 365 nm wavelength UV light and Ti O2 particles as the photocatalyst. Sodium tripolyphosphate and sodium glycerophosphate were used as the typical components of TP and the digested samples were then determined by spectrophotometry after phosphomolybdenum blue reaction. The effects of operational parameters such as reaction time and temperature were studied for the digestion of TP and the kinetic analysis of two typical components was performed in this paper. The pseudo-first-order rate constants k of two phosphorus compounds at different temperatures were obtained and the Arrhenius equation was employed to explain the effect of temperature on rate constant k. Compared with the conventional thermal digestion method for TP detection, it was found that the temperature was decreased from 120 °C to 60 °C with same conversion rate and time in this thermal-assisted UV digestion method, which enabled the digestion process work at normal pressure. Compared with the individual ultra-violet(UV) photocatalysis process, the digestion time was also decreased from several hours to half an hour using the thermal-assisted UV digestion method. This method will not lead to secondary pollution since no oxidant was needed in the thermal-assisted UV photocatalysis digestion process, which made it more compatible with electrochemical detection of TP.